As of March 2003, the Immigration and Naturalization Service (also known as “INS”) was split into three separate agencies. Customs and Border Protection (CBP) is responsible for enforcing immigration laws at the U.S. borders. The Immigration and Customs Enforcement (ICE) is responsible for enforcing immigration laws within the United States, such as seeking undocumented people. The U.S. Citizenship and Immigration Service (USCIS) helps with multiple immigration service functions: such as processing applications for permanent residence, naturalization, political asylum, as well as extensions and changes of non-immigrant visa status.